Mental contamination is the process whereby a person has an unwanted judgement, emotion, or behavior due to automatic processing. Greater susceptibility of older than young adults to mental contamination in social judgements has been well documented. However, relatively little is known about the processing mechanisms responsible for age differences in mental contamination. Preliminary studies demonstrated that source confusion mediated age differences in mental contamination. Older adults were more likely than young adults to misremember false information as true. The proposed project will examine strategies to counteract the effect of source confusion in order to eliminate age differences in mental contamination. It is expected that strategies of providing feedback during a source recognition task and deliberating by thinking aloud prior to social judgements will eliminate age differences in mental contamination. In addition, past research suggests that automatic activation of stereotypes may be another mechanism underlying mental contamination in social judgements. The present study will examine age differences in the automatic biasing effects of age stereotypes on social judgements. It is expected that older adults will be more susceptible than young adults to the automatic biasing effects of age stereotypes. Finally, the present experiments will manipulate levels of self- focus to increase self-awareness and counteract the automatic biasing effects of age stereotypes. The hypothesis is that source confusion and automatic activation of stereotypes are two processing mechanisms underlying age differences in mental contamination. Strategies to improve source monitoring and self awareness will counteract the automatic biasing processes in social judgements for young and older adults and will greatly reduce age differences in mental contamination. The immediate goal of this project is to provide a better understanding of the automatic biasing effects of source confusion and age stereotypes on social judgements of young and older adults. The long-term objective is to develop effective interventions to improve mental control for young and older adults.